CO2 vs. pH vs. Fish

[fishstah]

I've just set up a simple DIY CO2 injection system. I didn't go through the trouble to use any kind of fancy diffuser. I just used an airtstone. I didn't want to go through the trouble or money, and I'm more worried about the possible negative effects of too much CO2 on my fish. I only have a ten gallon. It was kind of a fun little science experiment to kill an evening with. My system looks to be air tight, so I guess that's good. I placed the airstone close to my filter intake. Will this kind of system effect my CO2 concentration at all? If it does, are the changes in Ph likely to have an effect on my fish? My cheap test strips tell me that my Kh is at 40 to 80 ppm, and my pH is roughly 6.8. I've never done anything to buffer my aquarium or alter the pH. I do have some driftwood.

 

[aqua_chem]

Whenever you're adding co2, you're going to be reducing the pH although it can be difficult to predict precisely how much. A 2L bottle on a 10g probably won't be enough to gas the tank, but if you're worried about it then you can watch for the first 24-48 hours to make sure your fish aren't showing signs of co2 toxicity.

 

[phin]

Since i've added diy co2 to my tank, I've added some baking soda to increase the KH from 3 to 4. my pH is unchanged from pre-co2 levels during photoperiods (6.6-6.8 ). During lights-out my pH drops to 6.4-6.6. I decided against any additional surface agitation with an airstone, I have a penguin 125 HOB and a fluval 206 canister which provides ample agitation. Based on my limited experience I don't think you need to worry about any adverse effects.

 

[aqua_chem]

Putting some crushed coral in a job filter is also one measure for peace of mind, and is a little more user friendly than baking soda.